Set WM_CLASS, WM_NAME and _NET_WM_NAME on the status bar window(s).
Set WM_CLASS, WM_NAME and _NET_WM_NAME on the status bar window(s).

The properties are set as follows:
WM_CLASS = "panel", "spectrwm"
WM_NAME/_NET_WM_NAME = "Status Bar - Region %d - spectrwm"
  (%d = region index starting with 1)

Closes #371

conformal/spectrwm,conformal/spectrwm,conformal/spectrwm